Despite many advances in post-stroke treatment, many patients develop immunological complications, which lead to increased morbidity and mortality. There is strong evidence that the immune system is altered following stroke, and that inflammation in particular, can play a role in the pathophysiology of cerebral ischemia. The current proposal will examine the effects of intraischemic and post-ischemic environment on immune response. Middle cerebral artery occlusion (MCAO) will be used to induce transient ischemia. Following experimental stroke, delayed-typehypersensitivity.( DTH) testing, KLH antibody production, and rate of wound healing willbe used as integrative measures of peripheral immune function (Aim 1). The influence of pro-social interactions (Aim 2) and social stress (Aim 3) on immune measures also will be examined. Taken together, the proposed studies will provide a foundation on which to study the effects of stroke on immune function and may provide insights into the treatments and therapies following an ischemic event that may improve the health of the patient.